Smoking ‘negatively affects breast cancer survival rates’

Smoking can negatively affect long-term survival chances after breast cancer, according to a new study conducted by the University of North Carolina at Chapel Hill (UNC), US.

The study was intended to examine whether smoking at the time of diagnosis and changes in smoking within five years after diagnosis were associated with long-term breast cancer mortality.

In a study of 1,508 women with breast cancer, subjects were interviewed and asked a variety of questions, including about smoking status. After five years, participants responded to the same questions.

The researchers explained that although breast cancer survival rates in the US are comparatively high - estimated at 90 per cent at five years after diagnosis - roughly 40,000 women are expected to die from breast cancer in 2017. They added that this makes breast cancer the second leading cause of cancer-related death among women.

In comparison to women who had never smoked, the risk of all-cause mortality was higher among the 19 per cent of at-diagnosis smokers.

Compared to women who had never smoked, smoking at the time of a breast cancer diagnosis was linked to a 69 per cent rise in the risk of all-cause mortality. This risk was increased by 50 per cent for current smokers who smoked fewer than 20 cigarettes per day and by 85 per cent for current smokers who smoked more than 20 cigarettes per day.

All-cause mortality was also higher among former smokers and current smokers who had smoked for more than 30 years, the researchers found.

Dr Humberto Parada, postdoctoral research fellow at UNC, said: “We considered the impact of post-diagnosis changes in smoking and show that quitting smoking after diagnosis may be important to improve survival among women with breast cancer.

“Future studies should continue to study the mechanisms by which smoking impacts breast cancer specific-survival.”